Antioch, California Pollen Count & Allergy Forecast

Antioch pollen count and allergy forecast — tree, grass, and ragweed seasons and what’s pollinating now

Antioch, CA · Pollen season

In September, ragweed pollen is in season in Antioch, peaking Aug–Oct.

Based on the seasonal pollen calendar for this region.

Antioch on the WeatherStory Allergy Index

Antioch isn't one of the 100 metros on the WeatherStory Allergy Index, but the nearest ranked metro — Concord, CA, about 11 miles away — sits at #49 with a 274-day combined pollen season.

#49of 100nearest ranked metro
Load index
34
Combined season
274 days
Heaviest load
Tree · 122 days
Nearest ranked metro
Concord, CA · ~11 mi

See the full 100 worst U.S. cities for pollen — a modeled seasonal load ranking (see methodology).

Typical now — Septemberseasonal estimate, not a live reading

Ragweed pollen typically leads in Antioch in September, at an estimated Moderate level.

Pollen by type this season

What pollinates near Antioch

The tree, grass, and weed species that drive Antioch’s pollen seasons, with each plant’s typical peak.

Trees

  • Oak Quercuspeaks March–April
  • Olive Olea europaeapeaks April–May
  • Coast live oak Quercus agrifoliapeaks March–April
  • Walnut Juglanspeaks April–May
  • Ash Fraxinuspeaks February–March
  • Mulberry Moruspeaks February–March

Grasses

  • Bermuda grass Cynodon dactylonpeaks April–June
  • Wild oat Avena fatuapeaks April–May
  • Perennial ryegrass Lolium perennepeaks April–June
  • Bromegrass Bromuspeaks April–May

Weeds

  • Common ragweed Ambrosia artemisiifoliapeaks August–September
  • Russian thistle Salsola traguspeaks July–September
  • Pigweed Amaranthuspeaks August–September
  • Sagebrush Artemisiapeaks August–September

Species are the region’s common wind-pollinated plants; peak months are a seasonal estimate, not a measured count — see methodology.

Antioch’s allergy year

Typical month-by-month pollen intensity for Antioch, tuned to its latitude and climate region — darker means higher typical counts. The highlighted column is the current month.

JFMAMJJASOND
TreeFeb–May
GrassApr–Jul
RagweedAug–Oct

How Antioch compares to the U.S. average

Each colored bar is Antioch’s typical season against the national-average window (grey). The offset is the per-city timing shift.

Tree~6 wks earlier
Grass~6 wks earlier
Ragweedabout average

“U.S. average” is the textbook tree Mar–May, grass May–Jul, ragweed Aug–Oct calendar. The shift is a phenology estimate (Hopkins’ bioclimatic law), not a measured count — see methodology.

How Antioch’s pollen count works

The calendar above is tuned to Antioch’s mild Mediterranean California climate, not a national average: tree pollen runs from week 5 (early February) to week 22 (late May), grass from week 14 (early April) to week 30 (late July), and ragweed from week 31 (early August) to week 43 (late October) here — a 274-day combined pollen season. Those windows are why ragweed pollen is the one in season in Antioch right now.

No live count is wired up for Antioch today, so the seasonal calendar above is your guide to which allergen is in season.

For the science behind Antioch’s pollen seasons — how counts are measured, when each type peaks, and what the numbers mean — see the pollen count scale and the other pollen & allergy guides.

Frequently asked

When is pollen worst in Antioch?
Tree pollen jumps the gun in Antioch, opening as early as Feb–May while colder regions are still dormant. Grass follows Apr–Jul and ragweed closes the year Aug–Oct. The early tree start is the trap — symptoms can begin before you expect them. Currently, ragweed pollen is in season.
What's in the air in Antioch right now?
In September, ragweed pollen is in season in Antioch, peaking Aug–Oct. On Antioch's mild Mediterranean California calendar the typical September level is Moderate, led by ragweed pollen — a seasonal estimate, not a live count.
Is tree or grass pollen higher in Antioch in spring?
In spring, tree pollen leads in Antioch — trees pollinate Feb–May, ahead of grass (Apr–Jul). The handoff is the tail of the tree window: tree counts taper as grass climbs, so an early-spring flare is more likely tree pollen and a late-spring one more likely grass.
What makes Antioch's pollen season distinctive?
Antioch sits in the mild Mediterranean California zone, which means an early start — mild winters pull tree pollen forward into late winter, ahead of a spring grass peak and a relatively contained ragweed fall. That shapes when symptoms hit and which allergen to watch.
How do I reduce pollen exposure in Antioch?
Through Antioch's peak windows (tree Feb–May, grass Apr–Jul, ragweed Aug–Oct), keep windows shut and run AC on recirculate; counts run highest on dry, warm, windy mornings, so push outdoor activity to late afternoon or just after rain, which clears pollen from the air. A HEPA purifier indoors, a saline rinse after being outside, showering before bed, and starting antihistamines a week or two before your worst local window all measurably cut symptoms.
When does the next pollen season start in Antioch?
Tree pollen is next in Antioch: it opens around week 5 (early February), peaks around week 11, and runs about 122 days.
What is the allergy forecast in Antioch today?
With no live reading for Antioch today, its allergy forecast is the seasonal estimate above: a typical September level of Moderate, led by ragweed pollen.